Improvement in differential gearings



W. D. ANDREWS.

lmpr'ov eme-nt-in- Differential-Gearing.

NO.128,352, v Patented June 25,1872.

m. Fum-umacMM/c mm: fossamlrs P300553) PATENT OFFICE.

WILLIAM D. ANDREWS, OF BROOKHAVEN, NEW YORK.

IMPROVEMENT IN DIFFERENTIAL GEARINGS.

Specification forming part of I etters Patent No. 128,352, dated June 25, 1872.

Specification describing an Improvement in Differential Gearing applicable to hoistingdrums and other purposes, the. invention of WILLIAM D.ANDREWS, of Brookhaven, in the county of Suffolk and State of New York.

This invention consists in a differential gearing for revolving an outside drum or wheel, composed of a central independent drivingshaft, which is provided with reversely-set or equidistantly-arranged eccentrics within the drum, and said eccentrics made to carry independent toothed disks or wheels, which, as the shaft is revolved, gear on opposite sides or at equal distances from each other, at constantly-varying points thereon, with an internal toothed rim or wheel fast to the drum and containing a greater number of teeth in it than either of the disks have in them, so that for each revolution of the independent central shaft the drum is moved a distance corresponding to the difference in the number of teeth in the internal gear of the drum and the number of teeth in either disk, and. so that the drum cannot slip orrotate, but is locked or held by 1 the toothedzdisks, and cannot be set in motion excepting as controlled by the movement of the central independent drivin g-shaft. The employment of severalthat is, two or moreequidistantlyarranged, eccentrics and a corresponding number of toothed disks carried by them produces a balancing action which materially assists in reducing friction and aids in the, smooth or easy running of the mechanism operating the drum; also, insures an enlarged or extended hold of the drum at equidistant points or places, thereby making said drum a perfect safety against slip. a

In the accompanying drawing which forms part of this specification, Figure 1 represents .a transverse section of a drum having my improvement applied to it, and Fig. 2 a longitudinal section thereof.

Similar letters of reference indicate corresponding parts in both figures of the drawing.

A is a drum arranged to turn on stationary sleeves or hollow bearings B B between standards O O.- Passing concentrically through said drum and its bearings B Bis an independent driving-shaft, D, which may be rotated by any suitable means. This shaft is formed with or has fast to it within the body of the drum oppositely-set or equidistantly-arranged eccentrics E E, which serve to carry and operate toothed wheels or disks F F of somewhat less diameter than the interior of the body of the drum, and so that, as the shaft D with its eccentrics E E is revolved, the toothed disks F F will be caused to gear, at constantly-varyingpoints and on opposite sides or at equidistant points simultaneously, with an internalwheel or gear, G, fast to the peripherical portion of the body of the drum. This internal gear G has a greater number of teeth in it than either of the toothed disks F F, so that on rotating, the shaft D with its eccentrics E E the disks F F will have a motion eccentric to the shaft around the interior of the drum, with which they always continue in gear without rotating about their own axes, and will thereby communicate motion to the drum equal to the difference in the number of teeth in either disk and in the drum or its internal gear G. Thus, if the internal gear G have one more tooth in it than either disk F, then for each revolution of the shaft D the drum A will be moved the distance of a tooth in the gear G. The toothed disks F F are supported and guided in their action by rollers 11 (1 carried by internal heads or flanges on the stationary sleeves or bearingsB B, and arranged to pass through circular openings 6 c in the disks.

By the employment of oppositely-set or equidistantly-arranged eccentrics E E and their toothed disks F F the working parts are balanced, one-sided action avoided, friction reduced, and gear constantly established with the wheel or gear G at equidistant points upon or in the drum, and whereby the strain upon the teeth is largely distributed, an effective application of the driving power communicated to the drum, and the latter held at equidistant points by the toothed disks against slipping or moving in either direction, except when the shaft H is rotated, thus making the drum a safety one.

Although only two eccentrics, E E, and two toothed disks, F F, are here shown, it will be obvious that three or more eccentrics arranged at equal distances from each other around the central shaft, and carrying a corresponding number of toothed disks, may be used.

Whatis here claimed, and desired to be secured by Letters Patent, is

1. The combination of the freely or independently hung drum A with the stationary sleeves B B and independent driving-shaft D, essentially as described.

2. The reversely-set or equidistantly-arpendent wheel or drum, substantially as speci ranged eccentrics E on or around the central porting rollers d d with the double-flanged stadriving-shaft D, in combination with the tionary sleeves B B,substantially as described.

toothed disks 01' Wheels F carried by said ec- WM. D. ANDREWS. centrics, and the internal gear G of the inde- Witnesses fled. FRED. HAYNES,

3. The combination of the guide and sup- R. E. RABEAU. 

